My words are coming from walking in your shoes, granted my exhusband was not an alcoholic, but a work alcoholic, and when he took our three daughters I was on pins and needles, as he would push envelope and go to certain extremes, of which I had zero control over, as the Judge warned me in court that I "must promote a healthy relationship with the non-custodial parent , or with a swipe of a pen, he could change custody."
As far as the playdates and other kids events, there certainly will be more events, and other playdates, you can't beat yourself up on this, kids really do not need to be on the go constantly, a bit of down time/ family time is ok too. ( and maybe just maybe, they can rebuild a relationship,)
It took a bit for me to realize that the girls really did enjoy their time with their dad, even though it was over the top activities, but in front of me they down played how much fun they had, because I think they were trying to protect my feelings, and not wanting me to feel left out. And yes, they were tired and crabby for a day or two after.
Certainly, I know the difference from an alcoholic, and a work alcoholic, but the ego, and selfishness , they both have in common, leave alot to be desired. But this is all new territory for everyone. My hope for your family, is, in time things will calm down, and there will be an element of normalcy. There relationship is "there's" to develop.
As long as he is not actively drinking in front of them, so what if they come home needing showers?
I've read your posts and I know this guy is a jerk, but I did not read in your post that he was drunk and put the kids in harm's way, please go easy on yourself here, it is an adjustment period.
(((hugs))))